发明名称 |
Trace vapor detection |
摘要 |
An apparatus is provided for detecting trace quantities of chemical species in the form of a vapor by subjecting ions produced in a sample of the mixed gas under flow to an ion repulsive electric field which is directed in the opposite direction to the flow of the gases, and comprises a fan for drawing the sample through a hollow body, having an inlet, a first region containing means for ionizing at least a proportion of the molecules of the sample by a corona discharge, a second region in which the sample is subjected to an oppositely directed ion repulsive electric field and a third region having an electrode for collecting ions of selected polarity. Ions of a selected polarity whose ionic mobilities exceed a value dependent on the strength of the ion repulsive electric field and the velocity of the gas flow are prevented from entering the third region. A resistor may be provided to limit the current of the corona electric discharge to a value not greater than 100 nanoamps.
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申请公布号 |
US4271357(A) |
申请公布日期 |
1981.06.02 |
申请号 |
US19790018801 |
申请日期 |
1979.03.08 |
申请人 |
PYE (ELECTRONIC PRODUCTS) LIMITED |
发明人 |
BRADSHAW, ROBERT F. D.;KRAICER, ALEC |
分类号 |
G01N27/64;G01N27/68;(IPC1-7):B01D59/44;H01J49/00 |
主分类号 |
G01N27/64 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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